Commercially available polymeric materials that have sufficient sulfur content to exhibit desirable sealing and fuel resistance properties for aerospace sealants and electrical potting compounds include the polysulfide polyformal polymers described, e.g., in U.S. Pat. No. 2,466,963, and the alkyl side chain containing polythioether polyether polymers described, e.g., in U.S. Pat. No. 4,366,307 to Singh et al. Materials useful in this context also have the desirable properties of low temperature flexibility characterized by a low glass transition temperature (Tg) and liquidity at room temperature.
Another desirable feature in polymers suitable for use in aerospace sealants is high temperature resistance. While incorporating sulfur to carbon bonds into a polymer generally enhances high temperature performance, —S—S— linkages in the polymer backbones can result in compromised thermal resistance.
There exists a need in the art for compositions, particularly those used in the aerospace industry such as sealants and electrical potting formulations, that may provide good pot life as well as good performance properties, such as fuel resistance, flexural strength, thermal resistance and/or longevity in use.